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  1. Building Regulations
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  3. Approved Document C (Resistance to contaminants and moisture)

Part C (Resistance to contaminants and moisture)

This section covers the technical guidance contained in Part C (Approved Document C) of schedule 1 of the Building Regulations.

It covers the requirements with respect to site preparation and resistance to contaminants and moisture.

Follow the links from this page to access the approved document, details of any previous appeals and determinations and further information relating to this part.

Approved Document C

Download the latest version of the Approved Document or view archived copies of previous versions

Research Reports

The Building Regulations are underpinned by research which aims to provide a sound scientific basis to the requirements and guidance relating to each of the technical parts.


Before bringing into effect changes to the technical requirements, or the supporting Approved Document(s), of the Building Regulations, Government seeks views on the proposed changes through a formal consultation process.

Regulatory Impact Assessments

Government departments assess the likely outcomes of regulating in order to try to achieve the right balance between under-regulating, which may fail to protect the public, and over-regulating, which may create excessive bureaucracy.

Part C - Determinations and appeals

The Secretary of State for Building Regulations may issue decisions on applications for determinations of compliance with the technical requirements of the Building Regulations, or appeals against a local authority's refusal to relax a requirement.

Associated documents (Part C)

The following documents are principally associated with the guidance relating to Site preparation and resistance to contaminates and moisture (Part C).